The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Vehicles may utilize a fuel pump to provide fuel to be combusted during operation of an engine. A fuel pump used to provide fuel to an engine may be a piston pump. The piston pump may be driven by a crankshaft output through a chain gear and cam.
In some vehicle operating conditions a requested fuel supply may exceed the capacity of a fuel pump configuration. For example, at vehicle cold start it may be desired to provide additional fuel to the combustion chamber. Increased fuel at cold start may be used with fuels such as ethanol blends, an example of which is an 85% blend of ethanol (E85). Another example of an operating condition requiring an increased fuel supply may be a heavy load where more fuel is required to power the engine.
In some vehicle operating conditions, the piston pump operation may not be optimal. For example, at high engine speeds the piston and cam may fail to engage properly. In such a “no-follow” condition the piston of the fuel pump may not stroke properly.